function Tab(el){
    this.el=document.querySelector(el)
    this.init()
}
Tab.prototype.init=function(){
    this.titleOver()
}
Tab.prototype.titleOver=function(){
    let ulLiObjs=this.el.querySelectorAll('ul li')
    ulLiObjs.forEach((item,i)=>{
        item.onmouseover=()=>{
              this.tbTitle(ulLiObjs,i)
              this.tbContent(i)
        }
    })
}
Tab.prototype.tbTitle=function(ulLiObjs,i){
     this.el.querySelector('ul li.active').className=''
    ulLiObjs[i].className='active'
    }
    Tab.prototype.tbContent=function(i){
        this.el.querySelector('ol li.active').className=""
        let olLiObjs=this.el.querySelectorAll('ol li')
        olLiObjs[i].className='active'
    }